Invalid bed



H.' FUHRER July 24, 1956 INVALID BED 2 Sheets-Sheet 1 Filed Aug. l2,1953 H. FUHRER July 24, 1956 INVALID BED 2 Sheets-Sheet 2 Filed Aug. l2,1953 mwen/0r Herbe/f Fahrer 5y his afforneys INVALID aan Herbert Fahrer,New Rochelle, N. Y., assigner to Edward J. Burke, Sr., New Rochelle, N.Y.

Application August 12, 1953, Serial No. 373,823

6 Claims. (Cl. 5-69) In beds for invalids it is customary to hinge thehead and foot sections so that those sections can be raised fromhorizontal position to any desired inclination. It is desirable thatthis raising and lowering be entirely automatic, and the use of electricmotor power units to actuate screw mechanisms to cause such movementshas been known heretofore. It is also desirable that the services of anattendant to adjust the bed be entirely eliminated. This is particularlyimportant when trained help is not available, as, for example, ininstances where the bed is being used in a home. In these instances thebed must usually be operated by the invalid. Thus l prefer to have theraising and lowering mechanism of my bed operated electrically by meansof push button switches available to the invalid.

in invalid beds having hinged spring sections it is desirable that therebe a thigh section and a foot section which can be raised together as arigid unit from the middle of the bed, and also that the knee jointbetween the thigh and foot sections be able to be raised while allowingthe foot section to hang down so that only 4the knees of the patient areraised. One of the objects of my invention is to provide whollyautomatic means permitting the leg portion of the bed, composed of thehinged thigh and foot sections, to be raised or lowered in either ofthese manners at the will c-f the patient without the intervention or"any manual manipulations by anyone. Another object is to achieve thesetwo wholly automatic operations without the use of more than one powerunit.

it is characteristic of an invalid bed made in accordance with myinvention that a rocker assembly is provided `etween the power unit andthe hinged sections of the bed, which rocker assembly can lift the legportion in either of the two manners mentioned, according to thedirection in which the rocker assembly is turned by its power unit. Italso provides electrical means integrated with the power unit and rockerassembly to give indivi-dual control of these movements.

in the drawings:

Fig. l is a plan View of a frame, power units and rocker assembly of aninvalid bed made in accordance with my invention, the spring beingbroken away except at one point.

Fig. 2 is a longitudinal section, taken on the line 2-2 of Fig. 1,through the middle of the bed and showing only the power unit for theleg portion of the spring.

Fig. 3 is a side elevation of the mattress and spring sec tions and partof the frame of the bed and rocker bar, showing the leg portion elevatedas a rigid unit.

Fig. 4 is a cross-section through the frame of thespring of Fig. 3 atthe point where it intersectsthe rocker bar.

Fig. 5 isa view similar to Fig. 3, showing the knee joint of the springelevated but the foot section hanging down; while Fig. 6 is a wiring-diagram of the electrical circuits for actuating the invalid bed ofFigs. 1-5.

The invalid bed of my invention preferably envisages the use of asectional mattress, and I-have shown as the Patented July 24, 151956mattress the one described and claimed in the U. S.

patent application of Edward J. Burke entitled Articulated Mattress andBed, led lune 15, 1951, Ser. No. 231,713 (now Patent No. 2,674,745). Asshown in that application and indicated by dotted lines in Fig. 3 0f thepresent application, the mattress has a section correspon-ding to eachhinged section of the spring of the bed. These mattress sections 10, 11,12 and 13 are preferably not fastened together but are held in positionlengthwise of the bed by retaining bars 14 fastened to the frame of thebed at the foot and head thereof. In the example shown in the presentapplication the spring of the bed is composed of four sectionscorresponding to the mattress sections. There is a head spring section15, a middle section 16 which is stationary and not raised, a shortthigh section 17 and a foot section 18. When horizontal, these fourspring sections rest on the upper horizontal member 19 of the frame ofthe bed. This upper horizontal member 19 passes completely around thebed and is welded to vertical legs 2i) to which in turn are connectedlower horizontal bracing members 21 at points intermediate the top andbottom of the legs. As suggested in the showing of Fig. l, springs 52can be supplied transversely of the spring sections of the bed toprovide the necessary support for the mattress, in any usual manner.

My invention relates more particularly to the means for raising thehinged sections, such for example as those constituting the leg portion,namely, the thigh section an-d the foot section. Ipropose to raise thesesections by electrically operated mechanisms which are adapted foreconomical use in the average home and which ycan be adjusted by the`occupant of the bed without leaving the bed. I have also shown meansfor raising and lowering the head section of the spring andan.individual power unit for raising and lowering `that head section. Thehead section power unit is powered by an individual electric motor andcontrolled by electric switches hereinafter described.

It is economically undesirable, both in initial cost and complexity ofopertaion, to have separate power units for operating the thigh and footsections. Yet it is highly desirable to operate those sections eithertogether as a whole rigid unit or separately so that the occupant of thebed can have his knees raised while allowing his. feet to hang down. lIhave invented a construction of bed by which it is possible for theoccupant to manipulate the foot and thigh sections .in either of thesetwo desired manners, and to do it all from a single power unit. In theexample shown in the drawings there are only two power units, one fortaking care of the leg portion and another to take care ofthe headsection. Thetwo power units are substantially alike, although they arenot of quite the same length. Each unit has a master screw 22 lyinglongitudinally of the bed. l mount these screws with one end pivotednear the foot of the bed and have them extend toward the head. There isa master nut `23 on the threads 24 on each master screw, and it is fromthis master nut 23 that I obtain the movement longitudinally of the bedto raise and lower the various sections. i The master nut is secured atthe left end of an innner tube 25, 25 telesupported from the frame ofthebed in anyV desired manner.

The inner tube, in the case of the power unit for the head, isidentified by the number 25 and is connected by a slotted hole 26 andpin 27 to an upwardly-extending curved arm 28 (Fig. l). The end of thisarm bends in the horizontal direction and underlies the support for thehead section of the spring. It will be seen that extension of the innertube will cause the head section of the spring to be raised from theneutral horizontal solid line position to the elevated position.

Referring now to the means for raising the leg portion of the bed, sinceit is desired to be able to raise the sections in two different manners,one would normally expect to use two power units. In order to keep thebed sufciently simple and inexpensive to make it available for use inthe home, I cause power activation of both the desired movements in sucha way that they can be individually controlled by electrical meansoperated from push buttons available to the occupant of the bed. Themeans of achieving the power activation of the foot and thigh sectionsas a single continuous inclined plane over the full length of the leg,and also causing activation of the thigh section by raising the kneewhile permitting the foot section to hang therefrom, includemodification of the power unit for the leg section and the electricalcontrols in the manners hereinafter set forth.

I have found that by making a hinged knee joint 33 with a solid backwhich permits the joint to hinge by moving upwardly but preventsoperation of the hinge in the opposite direction, it is possible toraise the leg portion as a complete unit on a continuously inclinedplane from the thigh to the free end of the foot section. This is doneby applying a lifting action t'o the foot section at a pointsubstantially closer to its outer end than to the hinged knee joint. Ihave found, however, that the knee joint can be raised in regular hingedfashion with the adjacent sections on opposite sides of the hingeassuming two oppositely inclined planes. The lifting action for thismovement is applied underneath the foot section at a point nearer theknee than the lower end of the bed.

T o furnish the lifting action at these two points I provide a rockerbar assembly such as shown in the drawings. The assembly contains twoidentical rocker bars 34 each lying longitudinally of the bed alongopposite sides thereof, the two being joined together by a tube 35. Thetwo rocker bars function identically. It will therefore be sufficient todescribe only one. The rocker bar has two open vertical slots 36, onenear one end of the bottom edge of the bar, and one near the other end.When the rocker assembly is in repose, i. e., in neutral horizontalposition, each open slot rests on a large rivet or pin 37, 38 extendinglaterally of the upper longitudinal member of the frame of the bed.These rivets are adapted to function as fulcrums for the rockerassembly.

Rigidly fastened to the tube 35 connecting the two rocker bars 34 andextending downwardly from the two bars is an arm 39 whose lower end liesslightly below the master screw 22 of the power unit for the foot of thebed. This arm is linked to the inner tube of the power unit by means oftwo links 40, 41 shown in Figs. l and 2. The connection between the twolinks and the inner tube is at the end of the inner tube away from thefoot of the bed. It will be seen that travel of the master nut 23lengthwise of the screw 22 will cause the rocker bars 34 to pivot on oneor the other of the two rivets or fulcrums 37, 38 above referred to.Thus if the master screw moves toward the foot of the bed its rocker barwill pivot about the fulcrum 38 which is furthest from the foot of thebed, applying upward movement to the foot section 18 of the spring at apoint nearer the foot than the knee joint 33, with the result that thefoot section and the thigh section are raised together as one rigidunit. Thus, in the example shown in the drawings if the screw 22 isrotated clockwise, the nut 23 moves toward the foot of the bed and therocker bars 34 pivot about the fulcrum 38 furthest from the foot of thebed, raising the entire leg portion as a unit from the hip joint (seeFig. 3). If

4 Y thereafter the screw is rotated counterclockwise, the en tire legportion of the spring, namely, both the thigh section and the footsection, is returned again to horizontal position.

To provide good contact between the rocker bars andl the frames of thespring sections, the angle iron forming those frames is supplemented, atthe point where eachrocker is located by an angle iron 53 extendinginwardly beyond the frame into position above the entire length of therocker bar. When the bar is rocked or tipped the upper end rides on theunder surface of the angle iron 53.

I so proportion my parts that when the master nut 23' for the legportion of the bed is approximately in the center of the threadedsection of the master screw 22, the rocker bars 34 are in horizontalposition. By arranging the parts in this manner, the master nut is movedtoward. the head of the bed by rotating the master screwcounterclockwise from the position shown in Fig. 2 where the rocker barsare horizontal. The depending arms 39 of the rocker assembly cause therocker bars to pivot about fulcrum 37 which is nearer the foot of thebed than ful-- crum 38, and upward movement is applied to the footsection at a point nearer the knee joint than the foot. This raises theknee joint in regular hinged fashion, causing the thigh section to beinclined upwardly from hip to knee while the foot section itself isinclined upwardly from the foot of the bed to the knee joint (see Fig.5). If while the screw is toward the head end of the bed it is rotatedclockwise, the master nut will move back toward its neutral position andthe elevation of the knee joint will be done away with and the entireleg portion will become horizontal again.

It will be noted that the two radii of the rocker assembly from fulcrumto its contact end of rocker bar 34 are different and that each fulcrumis specifically located tocause the rocker bars to contact the footsection at the proper point to accomplish the desired different angularlifting of the sections. T he two fulcrums make it possible to transmutedifferent parts of the normal axial motion of the nut and tube assemblyin o-ne direction into two different types of elevation of springsections. The use of separate switch connections for each raising andeach lowering of each of the different types of elevations permits safeoperation of the bed by the patient through simple push buttonelectrical mechanisms. Also included in the design is electricalstopping of the movements involved to tix the maximum and minimumpositions.

In order to preserve completely individual and separate control of eachof the above function, two separate electrically-controlled circuits areestablished through individual limit switches and separate hand pushbutton switches to the two motors 31 and 31 (see Fig. 6). It will benoted from this wiring diagram that I ernploy push button switches 42,43, 44 to control each of the above-described movements, but that therange of their operations is determined by limit switches. The pushbutton switch 43 is so positioned and located in the electrical circuitthat it can start or stop the raising and lowering of the entire legportion as a unit when the unbent knee joint is partially or whollyraised or when it is in the process of being raised or lowered. Thesituation is similar with regard to the push button 42 controlling theraising and lowering of the bent knee joint, and the push button 44controlling the raising and lowern ing of the head section. Each switchis a double-pole switch and also double-throw.

In the middle of the wiring diagram I have shown six limit switches, 45and 46 are the limit switches for the leg lift, 45 being for the toplimit and 46 for the lower limit. Limit switches 47 and 48 are for theknee lift, 47 being for the top limit and 48 for the lower limit. 49 and50 are the limit switches for the head lift, 49 being for the top limitand 50 for the lower limit.

The .limit switches for the leg portion can be seen in Fig. 2. They lieclose to the inner tube of the power unit to which they relate, atlongitudinal positions appropriate to cause operation at the propertimes according to the position of the master nut. Travelling with themaster nut and inner tube is an activating iin 51 adapted to operatethese limit switches. For example, the switch 46 for the bottom positionof the leg portion when coming from elevated leg position of Fig. 3 andswitch 48 for the bottom position coming from the elevated knee positionof Fig. 5, can be combined into one toggle rocker with arms 54, 55adapted to lie alternately in the path of the rod 51 extending laterallyfrom the tin 51 (see Figs. 3 and 5). Arms of this type permit theactivating rod to ride over them. ln this way any dead area iseliminated between two individual movements. There is no point in theoperation at which any desired movement in the normal range cannot besecured. Any movement can be stopped at any desired peint merely byreleasing the push button switch. Regardless of the functioning of thepush button control, the sections of the spring risc only to apredetermined maximum point, at which point electrical power isdisconnected. Similarly, electrical power is disconnected when a sectionreaches normal horizontal position if the switch being used is placed inthe down position as shown in Fig. 6.

lt will be seen that my device provides complete power-activatedarticulation of a bed spring, with a total of three individualmovements, using only two power units. Thus a greater range ofarticulation is provided with only trivial additional cost. The deviceis simple enough to be operated by the occupant of the bed.

What I claim is:

1. An invalid bed having a lixed frame, a spring on the frame havingmiddle, foot and thigh sections with hip and knee hinges joining themtogether, the knee hinge between the foot and thigh sections beingpivotable only in the upward direction from the horizontal; incombination with a bar assembly having a bar positioned to make slidingcontact under the foot section to apply lifting force thereto; saidassembly adapted to apply the force by tipping opposite ends of the barinto contact with dierent points on the foot section thereby to elevatethe knee hinge while letting the foot section slope down or to elevateboth the foot and thigh sections as a unit, and a power unit having ascrew attached to the assembly to tip the bar.

2. An invalid bed according to claim 1 in which there are fulcrums onthe frame at two points separated longitudinally of the bed, and the barof the assembly has notches adapted to move into and out of contact withthe fulcrnms, the assembly including linkage from the screw of the powerunit to the bar to tip the latter, said linkage being attached to thebar at a point unevenely spaced between the fulcrums, whereby the angleof elevation of the thigh section is ditferent for the same number ofscrew turns in the two directions of tipping the bar.

3. An invalid bed having a fixed frame, a spring on the frame havinghead, foot and thigh sections with head, hip and knee joints hingingthem together, the knee hinge between the foot and thigh sections beingpivotable only in the upward direction from the horizontal; incombination with fulcrum points on the frame at two points lyinglongitudinally of the bed and a bar assembly having a bar adapted to useone fulcrum when tipped to bring one end of the bar into contact withone part of the foot section of the spring and to use the other fulcrumwhen tipped to bring the other end of the bar into contact with anotherpart on the same spring section; said two contact parts separatedsufliciently so that the lifting force applied against one elevates theknee hinge and the force against the other elevates both the foot andthigh sections as a unit, and a power unit having a master screwattached to the assembly to tip the bar.

4. An invalid bed according to claim 3 in which the power unit has a nuttravelling on the master screw and linkage which connects the power unitto the bar assem bly moved by the travel of the nut on the screw; incombination with a motor adapted to rotate the screw in eitherdirection, the relation of the parts of the spring sections, barassembly and power unit being such that when the nut is intermediate theends of the screw the sections of the spring are horizontal; wherebytravel of the nut on one side of mid position produces movement of theknee hinge while allowing the foot section to hang down, and travel onthe other side produces movement of the foot and thigh sections as aunit.

5. An invalid bed according to claim 4 in which there are separateswitch circuits for controlling each type of raising into, and eachmanner of lowering from, each of said elevated position of the threespring sections, and a limit switch in each of such circuits, the limitswitches for the lowerings into the horizontal position being locatednear the mid position of the nut on the master screw and adapted to beactuated when the nutis near its mid position.

6. An invalid bed according to claim 5 in which there is a tin movingwith the nut to contact the limit switches; said tin and horizontalposition controlled limit switches being adapted to permit the tin tooperate but to pass those switches, the limit switches for controllingthe raising to each elevated position being at end positions of the nut;whereby the closing of a connection which causes the knee hinge to riseor the foot and thigh section unit to rise enables the bed to go fromone elevated position to the other as a continuous operation.

References Cited in the tile of this patent UNITED STATES PATENTS 90,449Hoag May 25, 1869 951,274 Gronde Mar. 8, 1910 1,265,253 Rust May 7, 19181,432,777 Mortimore Oct. 24, 1922 2,445,258 Beem July 13, 1948 2,617,117Putterbaugh Nov. 11, 1952 FOREIGN PATENTS 248,710 Switzerland May 15,1947

